摘要 |
The invention concerns an apparatus for determining the degree of variation of a feature in a region of an image that is divided into discrete picture elements, the feature being represented by complex valued signals, one for each picture element, the signal phase representing the feature class and the signal magnitude representing the certainty in the feature assertion. The apparatus includes a unit (3) for providing the complex valued signals (8) within the region and complex valued multiplication factor signals (9) corresponding to the complex valued signals. In a first summation unit (4), a first sum signal is generated by the magnitude products of the signals (8) and corresponding multiplication factor signals (9), and a second sum signal is generated by the complex valued scalar products of the signals (8) and corresponding complex conjugate of the multiplication factor signals. In a second summation unit (5), a third sum signal is generated by the signals (8) that are weighted with the magnitude of corresponding multiplication factor signals (9), and a fourth sum signal is generated by the complex conjugate of the multiplication factor signals (9) weighted with a magnitude of corresponding signals (8). A norming unit (6) is provided for norming the output signals from the summation units in a predetermined way (FIG. 2). |